Bit-brace head



G. ABRAHAMSON BIT BRAcE HEAD Aug. 23,1927. ,020

Fild Jan. 5, 1927 Patented Aug. 23, 1927.

UhliTED ST TES GUNWALD ABRAHAMSON, 0F POINT EDWARD, ONTARIO, CANADA.

BIT-BRACE HEAD.

Application filed January 3, 1927. Serial No. 158,683.

The present'invention relates to improvements in bit braces, and more specifically to improved and novel types of heads therefor.

The primary object of the invention resides in the provision of a bit brace head embodying means whereby the brace may be operated for the boring of holes in either a true horizontal or true vertical direction.

A further object of the invention is to provide a bit brace head embodying combined plumb and leveling means whereby the bit may be maintained in a level position when boring holes horizontally, and retained perfectly plumb both when boring downwardly or in the performing of an overhead boringoperation.

A further object of the invention is to provide a novel type of bit brace head embodying a combined plumb and levelling glass or bulb wherein the bubble will be visible to the operator both when boring horizontally and when boring vertically.

A still further object of the invention is to provide a novel type of bit brace head embodying; a combined plumb and leveling means for the bit brace, and which head may be readily substituted for existing types of rotatable bit brace heads.

A still further object of the invention is to provide a combined plumb and leveling bit brace head embodying a spirit bulb so mountec as to permit of ready substitution of a new bulb should the bulb become broken, and. which bulb is so mounted in. the head as to be fully protected against liability of becoming broken during ordinary usage of the bit brace.

A still further object of the invention is to provide a novel type or head for bit braces, wherein the head is mounted for rotation co-axially with the chuck of the bit brace, in a manner whereby when boring a vertical hole, the chuck may be maintained in a perfectly vertical or plumb position, and when boring a horizontal hole, the

chuck may be maintained in a perfectly level or horizontal position.

A still further 0b 'ect of the invention resides in the provision of a combined plumb and levelling bit brace embodying a spirit bulb adapted to be mounted upon the bit brace at a point to the opposite side'ot the sweep arm of the brace from which the chuck ot the brace is mounted, and thus allowing"- for the greatest variation of movement of tie spirit bulb without materially movii'i g of the chuck from either a true horizontal or vertical position. v

A still further object of the invention resides in the provision of a combined plumb and leveling head for bit braces wherein the sp rit bulb of the head, remains stationary our; rotation of the sweep arm, and thus allowing for the bubble to be visible to the operator at all times.

Other objects and advantages of the invention will be apparent during the course oi the toll wing detailed description, taken in connection with the accompanying drawing forming a part of this specification and in which drawing.

Figure 1 is a side elevation of a conventional type of bit brace showing my improved type of head applied thereto, and showing the brace in a position for boring a vertical hole.

Figure 2 is a view illustrating the brace in a position for boring a hole horizontally.

Figure 3 is a View showing the brace in position for boring a vertical hole overhead.

Figure 4 is an enlargedlongitudinal section throughthe improved type of brace head and showing the manner of rotatably mounting the head upon the brace.

Figure 5 is a section on a reduced scale on the line 5-5 of Figure 4;.

.Figure 6 is a. top plan view of theimproved type of brace head as illustrated in Figure 4.

Figure 7 is a side elevation of a slightly modified form of brace head.

Figure 8 is a sectional view on a reduced scale, taken substantially along the line 88 of Figure 7 and looking in the direction of the arrows.

Figure 9 is a fragmentary section through the term of head as illustrated in Figure 7.

Referring to the drawing in detail, and wherein similar reference characters designate corresponding parts throughout the several views, the letter A designates a bit brace of usual construction, and B the improved combined plumb and leveling head for the brace. The letter C may designate the modified form of construction for the brace head.

The brace A and which is of ordinary construction, embodies the usual U-sha-ped sweep or crank 10, having mounted on one all) arm thereof chuck 1]. which adapted for detachably receiving and retaining against rotation, a suitable bit not show and which bit when properly positioned within. the chuck 11 extends in axial alignment with the chuck. Provided at the upper or outer end of the sweep 10, the usual cylindrical stem portion 12 which extends in axial alignment with the axis of the chuck 11. In the example shown the end oi the stem 12 is provided with a reduced terminal portion 13 for providing a shoulder 1-2, and below the shoulder 14, the stem is provided with a circumi crentially extending groove 15.

Referring first to the preferred form of brace head as illustrated in Figures 1 to 6 inclusive and which is adapted to be rotatably mount d upon the stem 12 of the brace A, the same embodies a head proper or cap 16 which is adapted to be mounted a spirit bulb l7, and an attaching or coupling;

section 18 tor rotatably securing of the cap- 16 to the brace stem 12.

lhe heel proper or cap 16 and which is prefer-Joly formed of wood, is of ring like tormatiom and is provided with an axially disposed opening 19 which is preferably of circular formation. The opening 19 adjacent the inner or lower end. thereof, is reduced in diameter for providing an internal shoulder 20 which serves as an abutment for the spirit bulb 17.

deterring now to the spirit bulb l7, and w-ich iirelerably formed of glass, the same is of substantially barrel shap, form a bot y portion :21 which bulges out- Wt lly intermediate its ends and which body portion is closed at its outer end by means ol an oval shaped head 22 and at its inner end by means or" an oval shaped heat 7 its will be observed in Figure l the heads or ends and 23 are bulged outwardly with their highest or crowning points disposed the axial center of the body portion 21, while the body portion 21 is of greatest external. diameter at a point midway between the heads 22' and 2?}. lh'ovidcd at the outer end of the bulb 17 is an annularly extending rim 2% which ween the bulb is inserted into the opening 19, rests upon the internal shoulder 20 of the cap It in a manner whereby the bulb is disposed with its major portion project-in inwardly )ZlStthe inner face of the cap. A retaining rim or sleeve 2-5 is inserted in the opening 19 and engages the outer surface ol the rim 2i for retaining the rim in seating engagement upon the shoulder 24- with the bulb 17 disposed co-axially of the cap 16.

Extending in right angular relation to one another across the outer head 22 and traversing or intersecting atthe highest or crowning point of the head are plumb lines 96, while extending across the inner head 23 and intersecting at the highest or crowning point thereof, are plumb lines 27, the lines 26 and 27 serving as guide means when boring holes in a vertical direction. As will be observed in Figures 1 and 5, when the bubble designated by the numeral 28 is disposed so that the same lies concentric with the intersection of the plumb lines that such will indicate that a trulyvertical hole is being bored. When the brace is being used in a position as illustrated in Figure l, the plumb lines 26 the outer head 22 will be used for guide purposes, and when the brace is being used in an inverted posit-ion as illustrated in Figure 3, the plumb lines 27 will serve as a guide for overhead bow lug Extending circumterentially ot' the bulb body portion 21, and-at its'point of. greatest diameter, is a leveling guide line which comes into play when using the brace in a position as illustrated in Figure tor borir a truly horizontal hole. As will be observed in Figures and 4:. this leveling line 30 is disposed inwardly oi the inner face of the top 16 and at a location to be readily visible to the operator at all times during rotation of the sweep or crank 10.

Provided at the inner side of the cap 15 are diagonally extending cuts 31 which open into the bore oropening 19 for permitting oi? the operator to have view of the entire bubble in the spirit bulb when boring a hole in a horizontal direction;

Referring now to the attaching or coupling section 18 of the improved head B, and which serves as means for rotatably mounting of the head upon the stem 12 of the brace, the same is preferably formed of metal and embodies a flatring portion 32 which is secured in surface contact with the inner face of the cap 16 as by means of suitable screws 33 which may be threaded into the wooden cap 1.6. Extending from the ring 32, in converging relation to one another, is a suitable number of ribs or arms which connect at their inner ends in a suitable socket 35 provided with a terminal-- ly opening bore 36. This bore 36 extends coaxially with the spirit bulb 17 and is of a diameter to rotatably receive the cylindrical stem 12 of the brace A. Extending tangentially through the socket 35, is a retaining pin 87 which is adapted to move in the'circurnterential groove 15 for rotatably retaining of the head 13 upon the brace stem 12. As will be observed in Figure 4, the shoulder let of the stem 12 engages the inner end of the bore 86 and serves as a bearing for the head P. Thus it will be seen that the attaching section 18 aside from serving as means for rotatably mounting the head upon the brace A with the points or" intersection of the plumb lines 26' and disposed co-a'xi'ally of the stem 12, serves as a protection for the spirit bulb which projects inwardly from the cap 16 to a position whereby the bubble will be visible to the operator at all times during rotation of the sweep arm.

Referring now to the form of head C as illustrated in Figures 7. S and 9, the same is intended to function in a like manner as that of the head B, and embodies a. head proper or cap 40, a spirit bulb 41, and an attaching or coupling section 42.

The cap 40 is provided with a central opening 43 which flares outwardly at the inner side of the cap as at 44, and opening into the inner end of the opening 43, is a suitable number of recesses 45 and in the example shown three of these recesses have been provided at the inner face of the cap 40. ()pening at one edge of the cap 40, and extendinginto the oaening 43, is a sight opening 46 and which as will be obse'rved extends from the outer to the inner surface of the cap. A reinforcing strip 47 extends across the sight opening 46 at the outer side of the cap and may be secured at its opposite ends to the cap as by means of suitable wood screws .48. This strip 47 prevents splitting of the cap 40 and conforms with the circumference of the cap in a manner as to prevent injury to the operators hand when applying pressure to the head during boring operations.

Referring now to the spirit bulb 41, the same is of spherical formation, and is provided at a point outwardly of its center with three radiallyv extending lugs 49 one of which is adapted to seat in each of the reccsses 45 with the inner surface of the lugs preferably extending flush with the inner surface of the cap 40. The filler opening 50 for the bulb is preferably arranged in circumferential alignment with the lugs 49 and may extend into a suitable recess provided in the cap 40 As will be observed in Figures 7 and 9, the outermost portion of the spherical bulb 41 is disposed inwardly of the outer surface of the cap 40, and that the transverse center of the bulb is disposed inwardly of the inner surface of the cap.

Extending circumferentially of and intersecting at the inner and outer ends of the sphericalbulb 41, are plumb lines 51 which serve as guide means for use when boring holes in a vertical direction, and at different angles or degrees along at the vertical line 51. As will be observed in Figure 7, one of the plumb lines 51 preferably ext-ends centrally of the inner end of the sight opening 46. Extending circumferentially of the bulb 41 at the point of greatest diameter of the bulb, is a leveling line 52, and which as will be observed is disposed inwardly of the inner face of the cap 40 when the bulb is in proper position within the cap, As

illustrated by. the dotted line showing of for proper centering thereof when boring in a horizontal direction.

The attaching section 42 is of a construction practically identical to that of the attaching section 18, and embodies a substantial'ly fiat ring 53 which is secured to the inner face ofthe cup 40 as by means of suit-- able screws 54, and as will be observed this ring spans the sight opening 46 and serves as afurther brace for the dividedcap 40.

In both forms of head, it will be seen that the points ofintersection of the plumb lines are disposed coaxially of thechuck 11, and that the level lines encircle the bulb at a right angle to the plumb lines.

When using the brace as illustrated in Figure 1, the operator may readily view the bubble through the opening in the head proper; when using the brace in a position as illustrated in Fi ure 2 ma readilv view the entire bubble through the openings between the arms 34; and when using the brace in an inverted position as illustrated in Figure 3, may readily view the bubble through the openings between the arms of the attaching sections. By so rotatably mounting of the head upon the-brace stem, it will be seen that the spirit bulb will be retained stationary and thus allow the bubble to be visible to the operator at all times during rotation of the sweep or crank 10. It will also be observed that by so having the spirit bulb mounted at the greatest distance possible from the chuck 11, that slight variations of movement out of truly plumb or vertical positions, will not materially effect the angular position of the chuck 11 in which the bit is supported.

From the foregoing description it will be apparent that an extremely simple, novel, and eflicient type of bit brace head has been provided which may be readily applied to existing types of bit braces, and which head when in use will permit of the brace to be used in a manner for boring of holes in either a truly vertical or truly horizontal direction.

Changes in detail may be made to the specific forms of the invention herein shown and described, without departing from the spirit of the invention or the scope of the following claims.

I claim: Y

1. In combination with a head for bit braces, a spirit bulb carried by the head and provided with a plumb designation disposed co-axial with the chuck of the brace.

2 In combination with a head for bit luxran

braces, a spirit bulb carried by the head and provided wit-h traversing plumb lines intersecting at a point co-axial with the axis of the chuck of the brace.

3. In combination with a head for bit braces, a spirit bulb carried by the head and provided with a leveling delineation disposed in a plane at a right angle to the axis of the chuck tor the brace.

4-. In combination with a head for bit braces. a spirit bulb carried by the head and provided with a circumferentially extending leveling line disposed in a plane at a right angle to the axis of the chuck for the brace.

5. in combination with a head for bit braces, a spirit bulb for the head provided with plumb lines intersecting at a point c0- axial with the axis of the chuck for the brace, and a leveling line disposed in a plane at a right angle to the axis of the chuck.

6. In a head for bit braces, a cap, a spirit bulb carried by the cap and provided with guide delineations, and a coupling section of open construction whereby certain of said gude delineations are visible at the inner side of said cap.

4. In a head for bit braces, a cap, a coupling section of open construction and embodying a socket provided with a bore for rotatable mounting of the head, and a spirit bulb carried by the cap and projecting inwardly therefrom. into the open couplin section in axial alignment with the bore or said socket.

8.21 brace head of the class described comprising a cap, a spirit bulb carried by the cap and projecting inwardly therefrom, and a coupling section for rotatable mounting of the cap, embodying arms extending in converging relation from the inner side of the cap in spaced relation about said bulb, and a socket connecting the inner ends 01 the arms and provided with a bore arranged in axial alignment with the spirit bulb.

9. A brace head of the class described comprising a cap having an opening extendingaxially therethrough, a spirit bulb mounted in the opening and projecting inwardly from the inner face of the cap, and a coupling section for rotatable mounting of the cap, embodying arms extending in converging relation from the inner'side of the cap in spaced relation about said bulb, and a socket connecting the inner end of the arms and provided with a bore arranged in axial alignment with the spirit bulb.

10. A brace head of the class described comprising a cap provided with an axially disposed opening, a spirit bulb mounted in the opening and projecting inwardly from the cap, said bulb being provided at its inner and outer ends with traversing plumb lines intersecting at the axial center of the bulb, and a coupling section for rotatable mounting of t is cap, embodying arms extending inwardly in converging relation from the inner side or" the cap in spaced relation about said bulb and past the inner end thereof, and a socket carried by the inner end of the arms and provided with a bore arranged in axial alignment with the point of intersection of the plumb lines.

11. A brace head of the class described comprising a cap provided with an opening, a spirit bulb mounted in the opening and projecting inwardly past the cap, said bulb having its greatest diameter arranged inwardly from the inner face of the cap and provided with circumterentially extending leveling line at the point of greatest diameter of the bulb, and a coupling sectionfor rotatable mounting of the cap, embodying a socket spaced from the inner end of the bulb and provided with a bore having its axis extending at a right angle to the plane 01" the leveling line of the spirit bulb.

12. A brace head of the class described, comprising a cap provided with an opening, a spirit bulb fitting in the opening and projecting inwardly from the inner side of the cap, said bulb being provided with a leveling line spaced inwardy from the inner side of the cap and plumb lines intersecting at the inner and outer ends of the bulb, means for retaining the bulb in position within said cap, and a coupling section for rotatable mounting of the cap embodying a socket provided with a bore having its axis arranged in axial alignment with the point of intersection of the plumb lines.

GUNWVALD ABRAHAMSON. 

